Arc quenching device



Sept. 1,1931. 2 D. s. GUSTIN ARC QUENCI-{ING DEYIQE Filed Jajln. '11,1928 v INVENTOR D.-$. GUST/N ATTORNEY Patented Sept. 1, 1931 UNITEDSTATES PATENT: orrlcs DANIEL SNYDER GUSTIN, OF BLOOMFIELD, NEW .l'ERSEY,ASSIGNOR TO WESTING- HOUSE LAMP COMPANY, CORPORATION OF PENNSYLVANIA ABCoumvcnme DEVICE Application filed January 11, 1928. Serial No. 245,821.

This invention relates to electric incandescent lamps and moreparticularly to gas filled lamps having means therein for extinguishingan are occurring between the lead wires 5 of the lamp. Although thepresent invention is applicable to various types of lamps, it ispreferably applied'to gas filled lamps and particularly to such type oflamp in which a number ,of m lamps designed for a relatively low voltageare operated in series on circuits ofabout 200 to 600 volts or more asin street lighting and street railway lighting practice;

Heret-ofore, during the operation of such 1 lamps, certain disadvantagesoccurred by reason of an are forming between the lead wires of the lampwhen-the filament failed. It has been found that an are forming betweenthe lead wires is maintained for a considerable 20 length of time andoften not only traverses the leading-in wires to the stem-press or lowerportion of the lamp, but will actually burn a path through thestem-press and continue into the base portion ofthe lamp fusing 26 themetallic base into the socket or often destroying the socket andinjuring the adjacent arts.

p The formation of destructive arcs in lamps has been appreciablyincreased by the use of an argon as a gaseous filling for lamps insteadof nitrogen, since argon permits the formation and maintenance of theare more readily than does nitrogen, and although the present inventionis practical in an argon filled lamp, it has been found that -mo re.advantageous results are obtained when-a nitrogen filling is employed.

It will be evident that where lamps are operated in series, as, forexample, where five 110 volt lamps are 0 rated in series in a 550 voltcircuit, a conslderable area might be turned into darkness should onelamp burn out. Means are, however, provided in the form of various wellknown devices for closburns out. Some of such devices are incorporatedin the socket or in the socket holder and in order that they may besuccess- V fully operated, it is essential that an interso ruption ofthe current be effected when the ing the circuit around each lamp incase it filamentfails. Should an arc form between the leading-1n wiresand continue to permit a flow of current, the cut-out device would notoperate and as will be evident, the arc may continue to'the destructionof the said devices.

An object of the present invention isrto prov de a simple and effectivemeans'for terminating an are within a sealed envelope.

Another object of the invention is to prov1 de an arc quenching mediumso disposed w1th relation to the leading-in wires as to terminate an areoccurring therebetween.

Another object of the invention is to provide a medium between theleading-in wires of a lamp of such character that when an arc occurs thesaid medium will evolve gas or gases tending to, snuff the arc.

Other objects and advantages of the invention will be apparent as thedescription proceeds.

The invention will be more fully understood by reference to theaccompanying drawings in which:

- Fig. is an elevational view of a lamp embodying the present invention,partly brpiken away to show the interior thereof; an

Fig. 2 is a transverse sectional view taken on line IIII in 'Fig. 1.

Although the present invention may be applied to any suitableincandescent electric lamp, it is shown and described in the drawings asembodied in a gas-filled, ring type filament lamp comprising a bulb 10having the usual flare tube 11 sealed at 12 to the bulb. The flare tubeis of the usual hollow form having one'end terminating in a press 13from which an arbor 14 extends. The arbor is provided with support wires15 upon which a filament 16 is mounted. Leading-in wires 17 and 18extend through the press 13 and downwardly through the flare tube 11.

The type of bulb shown includes an exhaust tube 18' which occupies thecenter of the flare tube, this construction being common to theso-called tipless lamp. The lamp may be provided with the usual base 19in which the leading-in conductors 17 and 1 8 are electrically connectedin the usual manner at 20 and 21.

Normally, the leading-in wires or conductors 17 and 18 extend throughthe hollow portion of the flare tube 11 and if the filament 16 breaksand an arc occurs between the leading-in wires it would be possible forthe said arcto continue through the said flare tube and down into thebase. For. the purpose of quenching the are before it reaches the base,the flare tube 11 may be filled with a substance 22 capable of offeringa barrier between the leading-in wires to quench or snufl' the arc.

It has been found that a preferable material for-this purpose ismagesium carbonate. In practice, the said magnesium carbonate isutilized in a finely divided stateand is poured into the flaretube'until it fills the same. The

' powder may then be packedby tamping until it is compressed and firmlypacked about the leading-in wires after whicha collar or washer 23,preferably of felt, may be forced into the flare tube with a tight fitto hold the powder in place. If desirable, the washer may be furthersecured by applying a layer of a suitable cement 24 thereover.

When a lamp constructed as above set forth is put into operation and thefilament fails causing an arc between the leading-in wires, the said arcmay-travel down the leads until it is interrupted by the interposedbarrier of arc quenching material at which time the conductive passagenecessary for supporting an arc will be destroyed and the areterminated.

When employing the present are quenching medium in an argon filled bulb,it has been found that although the argon tends to sup port an arc, thepresent are quenching material serves to break down the are when saidmaterial is'reached. When using the said are quenching material such asmagnesium car bonate or like substance in a lamp having a nitrogen gasfilling, it has been found that the as evolved, which in the presentinstance is 0 gas, cooperates with the nitrogen to terminate the arc.

It is believed that the present arc quenching material is of suchcharacter as to absorb or dissipate electrons to such degree as toterminate the arc. The invention, therefore, contemplates any finelydivided material such as magnesium carbonate which will cooperate withthe gas within the bulb to terminate an are produced between elementsseparated by the arc quenching medium.

By reason of the present invention, a lamp may be produced with arcquenching means in a rapid and practical manner and at a cost comparablewith other lamp making operations. It'is appreciated that various typesof arc quenching devices have been produced, but the present inventionutilizes the standard structure of a lamp for the support of the arcquenching medium, thus avoiding any change in the accepted lampstructure and making the invention applicable to all types ofuniversally used lamps.

Although a preferred embodiment of the invention is shown and describedherein, it is to be understood that modifications may be made thereinwithout departing from the spirit and scope of the invention as setforth in the appended claim.

What is claimed is:

An electric incandescent lamp comprising a bulb containing nitrogen,leading in wires supported within said lamp, a filament mounted-on saidleading in wires and a quantity of finely divided magnesium carbonatedisposed between and in contact with leading in wires whereby gasesevolved from the magnesium carbonate upon the formation of an arebetween the lead wires cooperate with the nitrogen filling to terminatethe arc.

In testimony whereof, I have hereunto subscribed my name this 10th dayof January,

' DANIEL SNYDER GUSTIN.

